Final Report Summary - SOFT WETTING (Soft Wetting)
The performance of extremely soft materials lies at the core of many natural phenomena and technologies. Examples range from the deformation and growth of biological tissues, the soft contact lenses that we place onto our eyes, to the soft food products we consume. In this project we investigated the interaction of liquid drops with such soft materials: by combining experiments and theoretical modelling we revealed the fundamental laws that govern these "Soft Wetting" phenomena.
We have shown how the motion of droplets can be altered by the properties of the solid. For example, we discovered that droplets can interact with one another, mediated by deformation of the substrate. Remarkably, drops can be attracted or repelled upon varying the stiffness and the thickness of the soft layer. We have quantified these interaction forces in full detail, both theoretically and experimentally. As such, the project provides predictive tools that can be used to engineer soft smart surfaces for controlled drop coalescence and colloidal assembly, while the same mechanisms could play an important role in cell–cell interactions and adhesion to biological tissues.
In turn, drops have been exploited as versatile force-sensors that characterise soft materials with unprecedented resolution. Interestingly, we found that the deformation of soft solids are to a large extent governed by their surface tension -- a property that is usually associated to liquids, but equally affects the rigidity of gels, elastomers and soft tissues. This establishes an unexpected link between liquids and solids, offering a new perspective on the design of exceedingly soft materials. Our findings are currently explored and applied in the context of inkjet printing, slippery surface and the adhesion of solid and liquid materials of increasing complexity.
We have shown how the motion of droplets can be altered by the properties of the solid. For example, we discovered that droplets can interact with one another, mediated by deformation of the substrate. Remarkably, drops can be attracted or repelled upon varying the stiffness and the thickness of the soft layer. We have quantified these interaction forces in full detail, both theoretically and experimentally. As such, the project provides predictive tools that can be used to engineer soft smart surfaces for controlled drop coalescence and colloidal assembly, while the same mechanisms could play an important role in cell–cell interactions and adhesion to biological tissues.
In turn, drops have been exploited as versatile force-sensors that characterise soft materials with unprecedented resolution. Interestingly, we found that the deformation of soft solids are to a large extent governed by their surface tension -- a property that is usually associated to liquids, but equally affects the rigidity of gels, elastomers and soft tissues. This establishes an unexpected link between liquids and solids, offering a new perspective on the design of exceedingly soft materials. Our findings are currently explored and applied in the context of inkjet printing, slippery surface and the adhesion of solid and liquid materials of increasing complexity.